Valve control for concrete mixers



Jan. 19, 1932.. i s. SHAFER' JR 1,841,984

VALVE CONTROL FOR CONCRETE MIXERS Filed Mar ch 13, 192s I 26 V 27 INVENTOR.

Samuel dhafcnfi:

ATTORNEY Patented Jan. 19, 1932 UNITED STATES PATENT OFFICE SAMUEL SHAFER, JR., OF MILWAUKEE, WISCONSIN, ASSIGNOB- T0 CHAIN BELT COM- PANY, OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN vALv'n CONTROL non concnnrn MixERs Application filed March 13, 1928. Serial No. 261,381.

This invention relates to 'water control mechanisms for concrete mixers and has for one of its objects to provide a device of this character which will be simple in construction, comparatively inexpensive to manufacture and install, and more efiicient in use than those which have been heretofore proposed.

In certain of the well known types of concrete mixers in general use today there is pro- 5 vided a water receiving and measuring tank or receptacle, into which water from any suit able source of supply is introduced and accurately measured before being transferredinto the mixing drum, to the end that the ratio r between the amount of water and the amount of cement used may be accurately controlled. These water tanks are commonly provided with an inlet controlled by a valve and an outlet also controlled by a valve, and, in some instances, with an air escape check valve which serves to permit the escape of air during the filling of the tank and also to allow 1 the entrance of air during the emptying of M the tank, but which automatically closes when the tankbecomes substantially fullin order to prevent the overflow and waste of water.

While these measuring tanks are quite efficient for providing an accurate amount of water where sufficient time is allowed for 0 them to fill completely between discharges, it has been found to frequently happen in actual practice, particularly where the water pressure on the supply is low and the batches of aggregate for concrete are coming in quite 5 fast to the drum, that the operator will open the discharge valve from the tank before the latter has had a chance to completely fill. Inasmuch as the amount of water supplied to the mixing drum is dependent upon this tank being completely filled, it will be readily appreciated that, when the discharge valve is thus opened before the tank is completely filled, an inadequate amount of water will be supplied to the drum and, as a result, that particular batch of concrete will be unusually dry. This is of particular importance in View of the now generally accepted theory that the strength of the concrete is dependent upon' the ratio of water to cement, rather than upon the ratio of cement to aggregates, since, if

charge conduits and valves,

the requisite amount of water to completely hydrate the cement and preserve the watercement ratio is not provided, the strength of the resulting batch of concrete will be very materially lessened.

It is therefore one of the primary objects of this invention to provide means which will make it impossible for the operator to open the discharge valve before the tank is completely filled, and to thereby insure absolute uniformity in the amount of water discharged from the tank to the drum and consequentv preservation of the predetermined water-cement ratio.

With the above and other objects in view, whlch will appear as the description proceeds, the invention consists in the novel details of construction and combinations and arrangements of parts more fully hereafter described and particularly pointed out in the claim.

Referring to the accompanying drawings formlng a part of this specification, in which like reference characters designate like parts in all the views:

Fig. l is a perspective View of a Water measuring tank such as is commonly employed upon one well known type of concrete mlxer, together with its supply and disand showing one form of control mechanism constructed in accordance with the present invention applied thereto; and

Fig. 2 is an enlarged detail sectional view through the air escape valve of the liquid measuring tank showing its connection with the locking means for the inlet and outlet -valves of the tank.

Referring more particularly to the said drawings the numeral 5 indicates a liquid receiving receptacle, here shown as a closed cylindrical tank, which is provided with a conduit 6 serving both as an inlet and outlet conduit. The said conduit 6 is provided with actuating handle or lever 10 by means of which its movements are controlled.

Below the T connection 7 the conduit 6 is extended as at 11, to provide a water discharge which is connected to the mixing drum of the concrete mixer in any suitable manner, not shown. This discharge portion 11 of the conduit is provided with a control valve 12 having an actuating lever or handle 13, as will be clear from Fig. 1 of the drawings. A link 14 connects the valve levers 10 and 13 from which link extends a rod or other connection 15 to any convenient point upon the mixer, by means of which the valves may be actuated by the operator a well-known manner. In the form of the invention here shown, the link 14 is provided with a hole or perforation 16, which is adapted to receive one end of a sliding latch or rod 17, which passes upwardly through a suitable guide 18. The upper end of the rod 17 is pivotally connected as at 19 to one end of a link 20, the other end of which is pivotally mounted as at 21 in ears 22 carried by the bonnet 23 of the air escape valve 24 with which the tank is provided.

T his air escape valve, which forms no part of the present invention per so, may be of any suitable type, and is here shown as comprising a housing 25 in which is mounted the valve head 26' coacting with valve seat 27.

The head 26 is carried by a stem 28 which projects upwardly through the bonnet 23 with its upper .end in cooperative relation with the link 20 as clearly shown.

in the position shown in Fig. .1 it isassumed thatthe tank has been discharged and that the supply valve 9 is open and the discharge valve 12 is closed. WVith the parts in. these positions the lower extremity of the rod or latch 17 has entered the hole or recess 16 in the link 14 and, obviously, prevents movement of the valve levers and 18 and link 14 through the rod by the operator, so long as the parts retain these positions. It is therefore impossible for the operator to open the discharge valve 12 so long as the red 17 is in engagement with the recess 16, and this engagement will continue until the tank 5 has been substantially completely filled, at which time the level of the water which is entering under pressure, will rise quite rapidly, due to the decreasing dimensions of the upper portion of the tank; and

when the tank is completely full the water under relatively high velocity exerts considerable pressure upon the valve head 26 of the air escape valve 24 which will be forced upwardly against its seat 27 This upward movement of the head will be communicated through the stem 28 to the link 20, which will be swung about its pivot 21 and will lift the rod or latch 17, thereby disengaging its lower end from the hole or recess 16. When in this position, of course, the operator may move the link 14 through the medium of the rod or connection 15 and thereby move the valve control levers 10 and 13 to close the supply valve and open the discharge valve. hen this has been done the hole or recess 16 in the link 14 will have been moved out of alignment with the rod 17, and when the head 26 and stem 28 of the air escape valve 24 fall, thereby permitting the link and the rod 17 to again descend, the lower extremity of the rod 17 will engage and ride upon the upper surface of the link 14 until such time as the operator again moves the control rod 15 to move the link 14 back to the position shown in Fig. 1 to close the discharge valve and open the supply valve, at which time the lower end of the rod 17 will again drop into the hole or recess 16 and lock the valves against actuation until the tank has been again completely filled.

The valves 9 and 12 are preferably, although not necessarily, so set as to operate in sequence; that is to say, although the actuating levers 10 and 13 are moved simultaneously by the link 14, the fluid controlling elements of the valves are so designed, constructed and assembled that the one valve will be completely closed before the other one opens, and vice versa. This will eliminate any undesired passage of water from the measuring tank to the drum, through the opening of the supply valve 9 before the discharge valve 12 is completely closed.

The showing of the invention in Fig. 1 is more or less diagrammatic, and it will be understood that the invention in its broadest aspect contemplates the locking of the discharge valve in its closed position by any means until such time as the measuring tank shall have received a sul'licient amount of water to enable it to supply the predetermined quantity to the mixing drum when the discharge valve is open. Obviously various means might be devised for accomplishing this result.

It will therefore be clear that those skilled in the art may vary the details of construction as well as the precise arrangement of parts without departing from the spirit of the invention; and it is not wished to be limited to the above disclosure except as may be required by the claim:

hat I claim is:

In water supply mechanism for concrete mixers, a liquid receiving tank having an air vent; inlet and outlet pipes each having a valve controlling the flow of liquid to and from said tank; a link provided with an aperture, interconnecting said inlet and outlet valves; a valve operable by liquid within the tank, for controlling said air vent; a pivoted lever operatively engaging and movable by said air vent valve; and a rod carried by said lever, a portion of which enters the aperture.

in said link to prevent the closing of the Water inlet valve and the opening of the water outlet valve before said tank is completely filled, said lever being movable by said air vent valve as it closes upon completion of the filling of the tank, to Withdraw said rod from said link aperture, and thereby permit movement of the Water inlet and outlet valves to their closed and open positions respectively.

SAMUEL SHAFER, JR. 

